IPWM: An interval parameter water quality management model

This paper provides an interval parameter water quality management (IPWM) model and its application to a case study of water pollution control planning within an agricultural system. The model allows uncertain information, presented as interval numbers, to be effectively communicated into the optimization process and resulting solutions, such that decision alternatives can be generated through interpretation of the solutions (presented as stable intervals), which are flexible in reflecting possible system condition variations caused by the existence of input uncertainties. This IPWM solution feature may be favored by decision makers because of the increased flexibility and applicability for determining the final decision schemes. The method also does not lead to complicated intermediate models, and thus has reasonable computational requirements. Results of the case study indicate that reasonable solutions for agricultural activities in the study system have been generated. Sensitivity analyses of the effects of water quality/quantity restrictions on agricultural income are also provided to show trade-offs between different environmental/economic objectives.